Coloring textile materials



Patented June 25, 1940 UNITED STATES PATENT OFFICE 2,205,887 comma rnx'rnn MATERIALS Jean G. Kern, Hamburg,

N. Y., assignor to National'Aniline & Chemical Company, Inc., New York, N. Y., a corporation of New York No Drawing. Application June 2, 1988,

. Serial No. 211,390

14 Claims.

" lates more particularly to improvements in the operations employed for fixing the dye.

processing of textile fibrous material whereby the reduction of coloring agents on such materials is inhibited. ,(The term coloring as used herein and in the claims is meant to include dyeing and printing.)

An object of the invention is to provide inhibitors having improved actionagainst the reduction of coloring agents for textile fibrous material under reducing conditions.

Another object of the invention is to provide inhibitors having improved action against the reduction of vat dyes by the reducing agents generally used in dyeing and printing with vat dyes.

Further objects are the prevention of haloing and scratching in discharge printing processes, the prevention of marking-off in kier boiling, and the provision of a highly effective resist agent for resist printing.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

According to the usual methods of vat dyeing with anthraquinone, indigoid, thioindigoid and related vat dyes and various sulfur dyes, the dyes are rendered soluble by reducing them to the leuco or reduced form in an alkali medium. This conversion to the soluble leuco form is necessary in vat dyeing. However, in many cases it is desired to partly prevent this reduction. Examples of this are resist printing and dyeing under vat dyes, preventing undesirable facing effects in dis charge printing, alfi preventing marking-off in the kier-boiling of previously printed or dyed fabrics.

In resist printing, a so-called resist is printed on the fabric which subsequently is either padded or top-printed with the desired dye in reduced or unreduced form. The function of the resist is to prevent the dye from penetrating and becoming fixed on the fabric during the subsequent In general, compounds which prevent reduction of the dye are employed as the resists. While the process is more generally employed in vat dyes, it is applicable also to sulfur colors, basic colors, and other dyestuffs which are frequently applied to fabrics in their reduced form.

In discharge printing of fabrics, a dischargeable (reducible) dye is first applied to the fabric and then certain discharge agents, usually reducing compounds incorporated into a discharge connection with paste,are printed on the fabric in the places where it is desired to destroy the color. In practicing this discharge printing, several difficulties are often encountered. If there is an excess of the discharge agent in the discharge paste, a flushing or creeping out into the fabric beyond the design takes place, forming borders or halos around the print (so-called haloing).

If all of the discharge printing paste is not completely scraped off of the printing roller by the 10 doctor blade, the color is discharged along other lines than the desired design. A similar difficulty is encountered when a solid particle gets under thedoctor blade (so-called scratching), or when the printing paste is too thick, a thin film of discharge paste or tarnish being formed on the roller which is printed on the fabric and dulls or partially discharges and weakens the ground color (so-called facing).

Fabrics containing multi-coloredeifect threads produced with vat or sulphur dyes or printed goods are sometimes kier-boiled after weaving or printing. In this process, contact between the white and colored-effect threads or between part of the goods which has been printed and other unprinted parts frequently causes a partial transfer of the dye from the colored'to the other portion of the goods. This iscalled marking off. A similar bleeding effect is often produced in mercerizing fabric containing vat or sulphur-dyed effect threads; also on mercerizing completely vat dyed fabrics a lightening of the color sometimes occurs. These effects are apparently caused by the vat or sulphur dye being slightly reduced under the alkaline conditions in the kier or mercerizer, so that it becomes partially dissolved.

It has been attempted to remedy these difficulties with moderate success by the use of such substances as nitroaromatic sulfonic and carboxylic acids in dilute alkaline solutions, as well as phenolic compounds capable of develop ing a quinoid structure in alkaline solution, for instance, para-nitrophenol. Thus, mononitroand dinitro-benzene, toluene, phenol, and naphthol sulfonates have been heretofore proposed as inhibitors of the undesired reduction.

According to the present invention nitroaralkyl side-chain. sulfonates are employed as reduction inhibitors in connection with the coloring of textile fibrous materials. As employed herein and in the claims the term nitroaralkyl sidechain sulfonates denotes aralkyl compounds containing at least one nitro group as a substituent in the aryl nucleus and at least one sulfonic acid group or salt thereof as a substituent in the alkyl group, the term sulfonates generically including the free sulfonic acids and their salts. I have found if the sulfonate group is attached to an open-chain aliphatic radical which in turn is attached to an aromatic radical containing a nitro group, and especially if the sulfonate group is attached to a nitrobenzyl radical, that the efficiency of the sulfonate as a reduction inhibitor is far greater as compared to the sulfonates and carboxylates of nitroaromatic com pounds in which the sulfonate or carboxylate group is a nuclear substituent.

Thus I have found, in accordance with the present invention, that extremely low percentages of sodium 4-nitro-benzyl sulfonate entirely prevent marking off in kier-boiling, efficiently resist the printing and fixation of vat dyes and other reducible dyes, and entirely nullify the effect of excess undesired discharge agent.

A cross-dyeing effect is produced if the warp threads of any fabric are pretreated with a dilute solution of any of the nitro-aralkyl side-chain sulfonates of this invention and the fabric is subsequently printed with a vat dye in the regular manner. A unique effect of shading is thus obtained since the pretreated warp threads do not accept the vat dye while the filling presents the vat dye coloring in its fullest development. The soluble nitro-aralkyl side-chain sulfonates may be applied to the warp threads during their sizing prior to weaving. Thus the nitro-aralkyl sidechain sulfonates may be dissolved in the sizing material or slashing liquor and applied to the warp in the slasher in the regular manner.

The nitro-aralkyl side-chain sulfonates employed in accordance with the present invention may be represented by the following general formula:

where Ar is an aromatic radical, R is an aliphatic radical, preferably an aliphatic hydrocarbon radical, x and y are integers, and M is any cation. They include compounds in which the aromatic radical represented by Ar is free from further substituents or contains additional substituents; for instance, halogen and/or an alkyl, alkoxy, and/or a sulfo alkoxy group, etc. As examples of such compounds, the following are mentioned:

nitro-phenyl-octyl sulfonic acid nitro-phenyl-lauryl sulfonic acid nitro-chlorphenyl-hexyl sulfonic acid nitro-naphthyl-butyl sulfonic acid, etc.

I have found, however, that the most efflcient compounds are those in which Ar is a benzene radical, R is a methylene group, as is 1 or 2, and y is 1. Thus, the following compounds have been found to yield superior results as reduction inhibitors:

Z-nitro-benzyl sulfonic acid 3-nitro-benzyl sulfonic acid 4-nitro-benzyl sulfonic acid 6-chlor-3-nitro-benzyl sulfonic acid 2,4-dinitro-benzyl sulfonic acid 4=-chlor-3,5-dinitro-benzyl sulfonic acid The nitro-aralkyl side-chain sulfonates may be employed in the form of the free sulfonic acids or in the form of the salts thereof; the particular form employed being selected with a view to the nature of the other reagents with which it is to be employed. In general the alkalimined by a trial dyeing or printing. Thus, a. to 1 per cent aqueous solutions of the sodium salt of 4-nitrobenzyl sulfonic acid generally are ade quate for overcoming facing, haloing and scratching in discharge printing and in preventing marking off in kier-boiling and bleeding in mercerizing.

' Several embodiments of the useful application .of these compounds are discussed and shown in the following examples in which the parts are by weight. It is to be understood that these examples act merely as illustrations and not as limitations of this invention.

Preventing mark-01f in kier-boiling and mercerizing Example lv-lOOO kilos of unbleached cotton The exact amount necessary in agiven case can be easily detergoods containing woven-effect threads dyed with vat dyes are boiled in a kier for 6 to 8 hours at 10 to 12 lbs. superatmospheric pressure in a so-.

lution composed of 3 per cent caustic soda (based on the weight of the goods), 1 per cent soda ash and to 1 per cent of 4-nitro-benzyl sodium sulfonate. The goods are then soured, 'washed, bleached, soured, washed and dried in the usual way. No mark-off of the colored-effect threads on the white threads is then obtained, because of the reduction inhibiting action of the nitrobenzyl compound.

Example 2.Fabrics to be mercerized containing some vat dyed yarn are run on a mercerizing frame through a 25 per cent caustic soda solution containing 1 to 2 per cent of 4-nitrobenzyl sodium sulfonate. The cloth should be travelling at a speed of about 60 yards per minute and be in the alkaline solution for about 30- Resist printing under vat dyes A resist printing paste for obtaining a white resist may contain from to parts 014- 7 2,205,887 nitro-benzyl sodium sulfonate per 1000 parts of Example 5.A printing paste is made up as the usual paste. It. is recommended, however, that from 60 to 80 parts of zinc acetate be added in order to convert the sodium salt into the less soluble zinc salt of the nitro-benzyl sulfonic acid thereby avoiding the running and flushing of the print color. The calcium salt also may be used in some instances to advantage.

Example 3.Goods are,printed with the following paste:

Parts Gum arabic 300 4-nitro-benzyl sodium sulfonate 175 Kaolin 55 Water 390 Zinc acetate 80 Color index Carbanthrene Yellow G 1118 Carbanthrene Golden Orange 2RT 1097 Carbanthrene Red BN 1162 Carbanthrene Olive G 1150 Carbanthrene Blue BCS 1114 Carbanthrene Blue 3G 1109 Brilliant Indigo 4B (Tetrabrom Indigo) Example 4.Resists are obtained on warp yarns by running through a slasher box containing a mixture of potato starch and 5 per cent to 10 per cent of e-nitro-benzyl sodium sulfonate.

This sizing paste is then dried on the warps which are then woven into piece goods in the regular fashion. When these piece goods are printed or dyed with vat dyes, an excellent resist effeet is obtained on the warp yarns.

Colored resists The nitro-aralkyl sulfonate resist printing pastes may contain basic dyes or chrome dyes or am components such as nitrosamines, diazoamino compounds, etc. (for combination with coupling components on the fiber) whose dyeing properties are 'unaifected by the presence of the nitro-aralkyl sulfonates in order to produce colored discharge effects.

Basic dyes are unafiected by nitro-aralkyl sulfonates and therefore may be effectively used to produce colored resists under vat dyes. Basic dyes may be fixed by means of the conventional tannic acid and antimony salts or else in the form of their zinc lakes. In the first case, the cloth is printed with a printing paste containing the nitro-aralkyl body, the basic dye, and tannic acid, the printed material subjected to steaming and then passed through the usual antimony fixation bath to develop the lake, and is then padded with a reduced vat and further treated to fix the vat dye in the usual manner; for example, as above described in connection with white resists. It is much more advantageous, however, to apply the basic dyestuif'in theform of the zinc lake using 'resorcinol as solvent, as illustrated in the following example. I,

follows 20-40 parts of Rhodamine 6G Extra (C. I. 752) or any other basic dyestuff, are dissolved in 100 parts of resorcinol parts of H20. Then 150 parts of d-nitro-benzyl sodium sulfonate are added and then 300 parts of gum arabic 1:1

100 parts of water 120 parts of tannic acid 1:1

120 parts of zinc acetate or zinc lactate.

After being printed with this paste, the goods are steamed, then passed directly into the reduced vat dye solution (without the antimony aftertreatment), after which the goods are treated in the usual manner to fix the vat dye.

The vat dye does not take portion of the goods, which has the basic dye and contains the nitro-aralkyl sidechain sulfonate. The result is a printed design in the color of the basic dye on a vat dyed ground.

Example 6.A very brilliant azo red resist may be obtained on cotton, lowing procedure.

Cotton piece goods are impregnated (padded) with naphthol AS in the usual manner and then printed with a resist paste of the following composition:

Parts The diazonium compound obtained by diazotizing 18 parts of m-chlor-toluidine in the usual manner 120 Gum senegal 300 d-nitro-benzyl sodium sulfonate 15o Kaolin 50 Water 300 Zinc acetate 80 The nitro-aralkyl sulfonate does not interfere with the coupling of the naphthol AS and the diazonium compound, which results in a red dyeing on the goods in the printed portion. After printing, the goods are well dried, steamed for four minutes, then subsequently padded by passage through an alkaline hydrosulflte solution of a re- Parts Gum thickener 300 Manganese chloride 450 i-nitro-benzyl sodium sulfonate .4. 50 Aluminum hydrate (jelly) 200 After printing, the material is well dried and then dyed in a sulfur dye bath. These methods of application are well known to the art and-do not need to be described in detail.

Excellent. resist effects similar to those deon the printed become dyed by for example, by the fol- J to the specific examples.

scribed above also may be obtained by top-printing or "blotching the resist printed material with a vat dye printing paste, producing a so-called resist-blotch effect. The vat dye printing paste does not take on the resist printed part of the goods, thus giving a design partly in the color of the resist print and partly in the color of the vat dye print.

Discharge printing The use of the nitro-aralkyl side-chain sul fonates makes it possible to obtain perfect discharge effects on grounds dyed with insoluble azo dyestuffs, such as para-red or chrysoidine bister. In this case the dyed fabric is simply padded in an aqueous solution composed of from 2.5 to '1 parts per 1000 of 4-nitro-benzyl sodium sulfonate or any of the other nitroaralkyl sulfonate bodies of this invention.

It has also been found that when used under a discharge agent the nitro-aralkyl side-chain sulfonates produce several advantageous efiects. They prevent haloing, scratching and facing by oxidizing any excess discharge agent outside of the design. In addition, due to their slightly acid character, the nitro-aralkyl sulfonates act as a catalyst for certain discharges such as sodium formaldehyde-sulfoxylate which are definitely promoted by a slightly acid medium.

Example 8.-Cotton .or rayon fabrics dyed with 4 per cent of Erie Black GXOO (C. I. 581) are padded through a 0.1 per cent to 1 per cent solution of 4-nitro-benzyl sodium sulfonate and dried. The fabric is then printed with a discharge printing paste containing sodium formaldehyde sulfoxylate. It is found that haloing, scratching and facing have been effectively prevented and an excellent discharge efiect has been produced.

As above indicated, the invention is not limited Thus, the procedures, ingredients and proportions thereof employed in the above specific examples may be varied. The 4-nitro-benzyl sodium sulfonate employed in the examples may be replaced by any of the other nitro-aralkyl side-chain sulfonates herein disclosed, and especially by the monoand dinitro-benzyl alkali metal sulfonates.

I claim:

1. The method of inhibiting reduction of reducible dyes on textile material which comprises treating a textile material having a reducible dye applied thereto with a nitro-aralkyl side-chain sulfonate.

2. In the process of resist coloring, the step .which comprises applying to the fiber a resist composition containing a nitro-aralkyl sidechain sulfonate.

3. In the process of discharge printing, the improvement which comprises pretreating the goods with a nitro-aralkyl side-chain sulfonate.

4. In resist coloring of textile material, the improvement which comprises applying a nitrobenzyl sulfonate to the part of the material which is to resist coloring.

5. In resist coloring under vat dyes, the improvement which comprises printing the part of the material which is to resist coloring with a paste containing 4-nitro-benzyl sodium sulfonate.

6. In discharge printing, the improvement which comprises pretreating the goods with a nitro-benzyl sulfonate.

7 In discharge coloring with the aid of sodium formaldehyde sulfoxylate as a discharge agent, the improvement which comprises carrying out the discharge in the presence of an alkali-metal nitro-benzyl sulfonate.

8. In discharge printing, the improvement which comprises pretreating the material with an aqueous solution containing 4-nitro-benzyl sodium sulfonate.

9. In the processing of textile materials having a reducible coloring agent applied thereto by a treatment involving reducing conditions, the improvement which comprises carrying out the treatment in the presence of a nitro-aralkyl sidechain sulfonate as a reduction inhibitor.

10. In the processing of textile fibrous material in connection with the coloring thereof by a treatment involving subjecting a reducible coloring agent to reducing conditions in the presence of the fiber, the improvement which comprises subjecting the coloring agent and the fiber to the reducing conditions in the presence of a nitro-aralkyl side-chain sulfonate as a reduction inhibitor.

11. In the processing of textile fibrous material in connection with the coloring thereof by a treatment involving subjecting a reducible coloring agent to reducing conditions in the presence of the fiber, the improvement which comprises subjecting the coloring agent and the fiber to the reducing conditions in the presence of an alkali metal salt of nitro-benzyl sulfonic acid as a reduction inhibitor.

12. The method of inhibiting reduction of reducible dyes on textile material which comprises treating a textile material having a reducible dye applied thereto with a nitro-aralkyl side-chain sulfonate of the benzene series.

13. In resist coloring, the improvement which comprises printing the part of the material which is to resist coloring with a paste containing a nitro-aralkyl side-chain sulfonate of the benzene series.

.14. In discharge coloring with the aid of sodium formaldehyde sulfoxylate as a discharge agent, the improvement which comprises carrying out the discharge in the presence of a nitroaralkyl side-chain sulfonate of the benzene series.

JEAN G. KERN. 

